Overexpression of MsNAC51 from alfalfa confers drought tolerance in tobacco

Drought universally affects the development of agriculture, forestry, and pasture industries and has received extensive attention from researchers. However, the molecular mechanisms of how alfalfa (Medicago sativa L.), a widely cultivated perennial legume, defends against drought stress have remained unresolved. In this study, we identified a member of the NAC transcription factor family, MsNAC51, which was significantly induced under drought conditions in both the shoots and roots of alfalfa. MsNAC51 is localized in both the nucleus and the plasma membrane and is a transcriptional activator. Heterologous overexpression of MsNAC51 significantly enhanced drought tolerance in tobacco increased the accumulation of proline and peroxidase, and led to differential expression of a series of drought response-related genes. Further, we found that MsNAC51 could directly bind to the promoters of the proline synthesis gene MsP5CS and the reactive oxygen species scavenging gene MsPOD-P7, and promote their expression. These results suggest that MsNAC51 can enhance the drought resistance of tobacco and is a possible positive factor for drought resistance in alfalfa.